As unmanned autonomous vehicles (UAVs) become ubiquitous, the challenge of preventing UAVs from flying into restricted air spaces will become more complex and increasingly important. Examples of restricted airspace include but are not limited to airports, airplane flight paths, no-fly zones, buildings/skyscrapers, military reservations, stadiums, private property, and other geographic boundaries. Government aviation authorities are developing guidelines and regulations for UAV operations of all kinds (civil, commercial, recreational, etc.), including rules for controlling UAVs in and around restricted airspaces.
UAVs may be required to adhere autonomously to no-fly zone policies, which may proliferate as governments and individuals place restrictions on over flights by UAVs. No-fly zones may be include residences (e.g., where each residence may define overflight policies), irregularly shaped zones (e.g., parks, schools, airport facilities, etc.), time dependent zones (e.g., flight over schools permitted except during school hours), no-fly zones that are dynamic/condition dependent (e.g., flight over a park permitted, but not if the President is visiting the neighborhood). In rural areas, the density of restricted areas may be low, but in urban areas, the density of restricted areas may be high.